The implant stimulates activity in key areas of the brain, The New York Times reported.

The woman, in her early 40s, was a student when she was severely injured in a car crash 18 years ago. After recovery, she was able to live independently but had chronic fatigue and wasn't able to read or concentrate for long, making it impossible for her to resume her studies, hold a good job, or do much socializing.

"Her life has changed," since receiving the implant, according to study team member Dr. Nicholas Schiff, professor of neurology and neuroscience, Weill Cornell Medicine, told The Times.

"She is much less fatigued, and she's now reading novels. The next patient might not do as well. But we want keep going to see what happens," Schiff said.

The case was presented Saturday at a brain-science convention in Washington, D.C.

This is a test case, and similar results may not be achieved in other patients, experts noted.

"This is a pilot study," Dr. Steven Flanagan, the chairman of the department of rehabilitation medicine at NYU Langone Health, who was not part of the research team, told The Times.

"And we certainly cannot generalize from it. But I think it's a very promising start, and there is certainly more to come in this work," Flanagan said.

An estimated 3 million to 5 million Americans have disabilities related to traumatic brain injuries. Many of them are veterans of the wars in Iraq and Afghanistan, The Times reported.